Study on Degradation of 1,2,4-TrCB by Sugarcane Cellulose-TiO2 Carrier in an Intimate Coupling of Photocatalysis and Biodegradation System

Abstract

1,2,4 trichlorobenzene (1,2,4-TrCB) is a persistent organic pollutant with chemical stability, biological toxicity, and durability, which has a significant adverse impact on the ecological environment and human health. In order to solve the pollution problem, bagasse cellulose is used as the basic framework and nano TiO2 is used as the photocatalyst to prepare composite carriers with excellent performance. Based on this, an intimate coupling of photocatalysis and biodegradation (ICPB) system combining photocatalysis and microorganisms is constructed. We use the combined technology for the first time to deal with the pollution problem of 1,2,4-TrCB. The biofilm in the composite carrier can decompose the photocatalytic products so that the removal rate of 1,2,4-TrCB is 68.01%, which is 14.81% higher than those of biodegradation or photocatalysis alone, and the mineralization rate is 50.30%, which is 11.50% higher than that of photocatalysis alone. The degradation pathways and mechanisms of 1,2,4-TrCB are explored, which provide a theoretical basis and potential application for the efficient degradation of 1,2,4-TrCB and other refractory organics by the ICPB system.

Prospects for Combined Applications of Nanostructured Catalysts and Biocatalysts for Elimination of Hydrocarbon Pollutants

“…Today, hybrid processes such as ICPB are known for the degradation of hydrocarbon pollutants (Table 3) [99,[102][103][104][105][106][107][108][109][110] and some persistent and toxic organic pollutants [97]. At the same time, it can be argued that research in this direction is currently almost at the initial stage of development but will actively advance in the near future.…”

“…Among the known ICPB processes involving NCs, processes with TiO 2 and its derivatives predominate, which provide the destruction of toluene [102], phenanthrene [105], pyrene [106], phenol, 4-chlorophenol (4-CP) and 4-fluorophenol (4-FP) [107], 1,2,4-trichlorobenzene [108] and petroleum refinery wastewater [99].…”

“…For those processes, where a comparative assessment of the effectiveness of joint and separate applications of biocatalysis and photocatalysis was carried out, the ICPB priority was shown [106,108]. The processes of hybrid biological and photocatalytic degradation of PAHs in soil with Ag 3 PO 4 @Fe 3 O 4 and in water with Mn 3 O 4 /MnO 2 -Ag 3 PO 4 have been studied with the combined use of microbial BCs and NCs with photocatalytic activity in visible light [103,104].…”

“…Microcapsules based on Ca-alginate gel and carboxymethyl cellulose successfully protected BCs from direct contact with the photocatalyst and free radicals, increasing the life of BCs during the photocatalytic decomposition of PAHs [103]. Cellulose used as a carrier provided conditions for the growth of cells of the genus Ruminiclostridium used as BCs and played an additional role of co-substrate [108]. In this case, the cellulose carrier was not only biocompatible but also biodegradable.…”

“…The presence of a co-substrate or its formation in the workflow can contribute to improving the efficiency of the implementation of hybrid processes. Not only the carrier but also low-molecularweight substances (acetic or propionic acids formed in the bioreactor or introduced from outside) can also act as co-substrates and electron donors and contribute to the course of photocatalytic reactions [108]. Today, the development of hybrid processes depends on the development of three-dimensional carriers characterized as affordable, high strength, biocompatible, porous and reproducible in characteristics.…”